Edwakd hewett



E. HEWETT. Chimney Gow].

Patented Nov. 2, 18691 gttnmegz.

taint sear new amm- Letterslatent No. 96,430, dated Not-ember 2, 1869.

CHIMNEY-COWL.

The Schedule referred toin these Letters Patent and making part of thesame.

To all whom it may concern Be it known that I, EDWARD Hnwmr, of -St.Lconards-on-Sea, in the county of Sussex, England, have invented-a newand useful Improvement in Cowls for Ohimneys and Shafts: andl do herebyde-' clare that the followin is a'full, clear, and exact descriptionthereof, which will enable those skilled in the art to make and use thesame, reference being bad to the accompanying drawings, forming part ofthis specification.

My invention relates to improvements in the construct-ion of cowls, tobe applied to chimneys and furnace-shafts, whereby an efficientlip-draught is obtained and downdrzuight at the same timeis prevented.

According to my invention, I form the cowl of a tube of i-ronsiderableheight, and of about the same diameter as the chimney itself, abovewhich it ismounted, so as to turn on a vertical pivot, fastened to thechimney.

The top of this tube may either be closed, and provided with an apertureat one side for .the exit of the smoke, or it may be of curved form,like an ordinary cowl, and in each case provided with a suitable vane.

The top of the chimney is provided with an annular inclined plane forthe support of the cow], near the lower end of the cow], and at theopposite side of the exit-opening above mentioned is a fininel-shapedopen ing for the-admission of air, which (as thc opening is always keptfacing the wind by the action ot'the vane at top) rushes in and passesup the annular space surrounding an inner smokedube, and out at the topof the cowl.

The air, in passing. out of the cowl, carries the smoke with it, thuscreating a strong upward draught in the chimney.

A modification of this arrangement consists in dispensingwith thecentral smoke-tube, and providing the revolving cowl with a longitudinaldiaphragm extending about halfway up the same.

The cowl is thusdivided into two parts, one of which is open to thechimney for the passage of the smoke, and the other cimmiunicating, asbefore, with the outer air, admits astrong upward current of air throughthe cowl, which carries the smoke with it, and produces the draughtdesired.

In each case I prefer that the volume of air admitted through the cowlshould 'be at least equal to the volume oi smoke escaping at the top ofthe chimney.

These cowls are'applicable to most kilns of similar structure, and toair-shafts for vent-ilatirig-purposes; also for raising gases and vaporswhich are either lighter or heavier than atmospheric air.

Figure 1 represents a side elevation of one arrangement of cowl of myinvention;

Figure 2 is a vertical section of the same, showing the internalarrangement;

Figure 3 is a .side view of a modification of the SHIT! I Figure '4, avertical section of said modification; and v Figure 5, an end viewof'thc same.

Similar letters of reference indicate corresponding parts.

A is thet-ube forming the cowl, mounted above the chimney-top B on avertical md, O, fixed to the chimney-top B, on. which the cowl turns ona pivot.

The upper end of the tube- A is closed, and'an aperture 1), is providedon oneside for the exit of the smoke. I

The upper part of the cowl may be of curved form, like an ordinary cowl,in any case being .provided with a suitable vane or vanes, F.

Within the tube of the cowl is arranged a central smoketube, F,.of abouthalf the diameter of A.

' The top of the tube F is diverted into the same.

direction with the upper part 1), of A, as seen in fi 2.

At the lower part of the cow], and at the opposite side of .theexit-opening D, above mentioned, is, in the pipe A, an opening, G, forthe admission ot'.air, to facilitate which, the opening G may further bepro.- vided with a funnel-shaped month, if desired.

As this opening G is'always kept facing the wind, by the action of thelatter on the vanes E, the air entering the cowlpasses up the annularspace H, contained between the smoke-tube Fand the out-er tube A of thecowl, and out at the exit-tube D at the top oi'the cowl, creating astrong upward draughtin the chimney, for extracting the smoke containcdaIn order to prevent the cowl from being carried away by the wind, and atthe same time to allow pcrt'cct freedom in turning, Iprovi'de the cowlwith the central tube 1, as seen; which surrounds the pivot G throughoutthe greater part of its length, thereby preventing the removalof thecowl by the wind.

J J are flanges formed around the base of the cowl and the top ofchimney B respectively, to prevent the admission of the wind or rain,and to form as nearly as possible an air-tightjoint.

The arrows show the direction of the smoke, and

which case the bent upper part must be dispensed with.

The central smoke-tube F may" be entirely dis pensed with, and aninclined diaphragm in the lower part ot'the tube A, substitutedtheretor.

This diaphragm may only be. carried. about half way up the cow], but Iprefer to carry it entirely up.

The lower part ot'the cow] is thus divided into two parts, the one ofwhich is open to the chimney B, for the passage of the smoke, as seem,aml the other, communicating, as before, with the outer air, admits astrong upward current of air through the cowl, which carries the smokewith it, and produces the up-dranght desired.

According to another arrangenu-nt illustrated in figs. 3, 4, am] 5, lmount the cowl A at an angle to. cliinmey .8, instead of being in linetherewith, as before. I

The smoke-tube F, to which the cowl is fastened, passes first upwardperpcmlicularly and is then carried at the same angle as the cowl A, inwhich it occupies a central position, as seen.

By this alrangement the smoke is divertedfi'om its perpemlicular courseinto a line with the constant current of air passing through the annularspace It bciin-e coming in contact therewith.

A l'unnel may in thiscase also be formed at the lower end of the cowl,to facilitate the entrance ot'the air which passes through the annularspace H, and mixing with the smoke betiu'e it leaves the cowl, creates astrong upward current in the chimney.

The filllukt tllbe F is in this way supported in the chimney in the samepanncr in which the cowl is held in fig. 2..

An inclined diaphragm placed in the inclined cowl, may be substitutedtor the. smoke-tube F, aml would be so placed as to deflect the smoke onentering the cowl; a second diaphragm serving to closeup one halt of thechimney-aperture, and cause the smoke, on issuing therefrom, to passbetween the two diaphrag'ms in an inclined upward direction.

The air passes through the cowl above the first diaphragm, also in anupward direction; by reason of its slanting 1msition,-a1u.l catching thesmoke before leaving the cowl, creates the draughtrequired.

' In order to prevent an accunullation of soot in the severalsmoke-tubes I, which are inaccessible to the brushes orcleaning-devices, one or more balls of cork or other suitable materialmay be placed in said tubes, the balls beingretaiued therein by wirenetting placed at the top and bottom of the. tube. These balls aremaintained continually in motion by the cnrrentof air created in thetube, thereby preventing thesoot from lodging therein.

The, tubes composing the improved cowls, of my invention, inay either becylindrical, as shown, or in the form of truncated cones, or ot'othershape.

Having thus described my invention, 7

What 1 claim as new, and desire to secure by Lettcrs Patent is--' a l. A(shimmy-cowl, provided with an air-tube and smoke-pipe, whose outletsare nearly in the same vertical plane, as shown and described.

2. A chinnu-y-cowl, provided witlr the tube T, to preserve. it in itsexact vertical position, as set forth.

3. A smoke-tube, provided with abuse, attached to the chimney by'twointermediate bevelled flanges, J J, to make a tight joint, as set forth.7

The above specification of my invention signed by me, this day ot May,1869. I

EDD. HEWETT.

Witnesses:

A. M. CLARK, James DL'ISH,

i 53 Chancery Lane, London.

